The date palm tree (Phoenix dactylifera L.) is an economically important plant in Arab countries, particularly the Gulf countries. The Gulf countries produce approximately 50% of dates worldwide, according to the UN Food & Agriculture Organization (FAO). The Kingdom of Saudi Arabia (KSA) is a major date producer. More than 25 million date palm trees grow on 157,000 hectares and produce around 1.1 million tons per year of date fruits, according to the Ministry of Agriculture.
Each date palm tree generates around 40 kg of dried, burnable agro-waste annually, which includes sheaths, dried leaves, petioles, and spathes. The dried agro-waste materials are not suitable for animal feed and only a small amount of the agro-waste finds use in limited traditional applications, such as shading, house construction, crates, handicrafts, landfilling, and panel boards. As such, a huge amount of date palm agro-waste is not utilized and instead creates an environmental nuisance. Therefore, it is desirable to find a use for agro-waste, particularly through new techniques and products.
Nanostructured materials (NMs) can be useful in electrical, optical, catalytic, and biological applications. NMs exhibit shape, size, surface area, chemical composition, and aggregation state based on their physical, chemical, and biological properties and can differ entirely from bulk materials with the same composition. Moreover, NMs can improve product quality, efficiency, stability, and function in various sectors, including textiles, food, agriculture, information technology, electronics, energy, and medicine. NMs have particular promise as a versatile toolbox for biomedical applications, such as antimicrobial agents, contrast agents in bio-imaging, scaffolds for tissue engineering and 3D-cell culture, disease diagnosis and therapy, and as drug and gene carriers.